Improved Left Atrial Function in CRT Responders: A Systematic Review and Meta-Analysis

Abstract

Cardiac resynchronization therapy (CRT) is associated with reverse left atrial (LA) remodeling. The aim of this meta-analysis was to assess the relationship between clinical response to CRT and LA function changes. We conducted a systematic search of all electronic databases up to September 2019 which identified 488 patients from seven studies. At (mean) 6 months follow-up, LA systolic strain and emptying fraction (EF) were increased in CRT responders, with a −5.70% weighted mean difference (WMD) [95% confidence interval (CI) −8.37 to −3.04, p < 0.001 and a WMD of −8.98% [CI −15.1 to −2.84, p = 0.004], compared to non-responders. The increase in LA strain was associated with a fall in left ventricle (LV) end-systolic volume (LVESV) r = −0.56 (CI −0.68 to −0.40, p < 0.001) and an increase in the LV ejection fraction (LVEF) r = 0.58 (CI 0.42 to 0.69, p < 0.001). The increase in LA EF correlated with the fall in LVESV r = −0.51 (CI −0.63 to −0.36, p < 0.001) and the increase in the LVEF r = 0.48 (CI 0.33 to 0.61, p = 0.002). The increase in LA strain correlated with the increase in the LA EF, r = 0.57 (CI 0.43 to 0.70, p < 0.001). Thus, the improvement of LA function in CRT responders reflects LA reverse remodeling and is related to its ventricular counterpart.

Predictors of Higher Frequency of Atrial Fibrillation in Patients with Cardiac Resynchronization Therapy

“…Lack of both reverse LV remodeling and decrease in MR severity affects LA hemodynamics and size. The effect of LV remodeling on LA function was described in a meta-analysis by Bytyçi et al, who reported improvement in LA hemodynamics and function in patients responding to CRT [49]. On the other hand, it is known that MR also works in favor of AF.…”

Atrial fibrillation in cardiac resynchronization therapy

“…This may be related to the effect of reverse LV remodeling on left atrial hemodynamics, and improved left atrial function has been demonstrated in CRT responders who are in sinus rhythm. 41 Furthermore, up to 40% of patients indicated for CRT have significant functional mitral regurgitation, owing to combination of LV dyssynchrony and dilatation, and improvement in mitral regurgitation severity has been reported in 23%-49% of patients after CRT in clinical trials. 42 Mitral regurgitation has a complex interaction with AF, and has been associated with poorer outcomes after ablation.…”

Special Issue: Latest Advances in Delivery and Outcomes of Cardiac Resynchronization Therapy and Conduction System Pacing

“…Reverse left ventricular remodeling is thought be the best predictor for these cardiovascular endpoints. It has been suggested, however, that left atrial reverse remodeling as a possible marker for atrioventricular resynchronization should be included in follow-up examinations [5][6][7]. The amount of reverse remodeling that defines a responder is also a subject of debate.…”